Patch for KEditToolbar dnd support

[Sandro Giessl]

Hello,

Would anyone mind reviewing the following patch? It adds drag&drop 
support to KEditToolbarWidget.
http://sandro.giessl.com/files/kedittoolbar_dnd.diff

Sorry, it's quite long. Basically what it does is:
- Replace the KListViews with a subclass enabled for dnd using a custom 
QStoredDrag subclass.
- Move the private list view mmbers to the d pointer, but keeps the old 
members. This hopefully keeps binary compatibility.
- Some code to handle dropped() signals...

Especially why I'm CCing to kde-core-devel is because I'm unsure about 
the DragObject stuff. For example, is it ok to simply choose a random 
"data/x-kde.toolbar.item" mime type name for the toolbar item data or 
is there anything to consider when creating a new mime type?

thank you,
  Sandro